Dry emulsions prepared from saccharose (SAC), Labrafil® M 1944 CS, sesamol (SEOH), and hydroxypropylmethylcellulose (HPMC) or sodium caseinate (SC) by grinding or dissolution, and
different desiccation techniques (spray (SD)- or freeze (FD)-drying, or heating at 60 °C) were investigated to determine possible
interactions between mixture components. The goal of this study was to determine the best formulation which will regenerate
perfectly, after water dilution of dry emulsions, the initial liquid emulsion with the same characteristics that before drying.
The morphological state of SAC and dry emulsions were determined by scanning electron microscopy analysis (SEM) analysis.
Glass transition temperature, and melting (endothermic), decomposition (endothermic), oxidation (exothermic) peak temperatures
and enthalpies were measured by differential scanning calorimetry (DSC). The antioxidant activity of emulsions was evaluated
through their ability to reduce 1,1-diphenyl-2-picrylhydrazil (DPPH) free radical. SEM analysis showed that SD-prepared, SC-containing
dry emulsions formed better spherical particles with smooth surface at about 5 μm diameter as compared to emulsion containing
HPMC. These former emulsions also showed more thermal stability by DSC. The combined results of the three analytical techniques
emphasized the importance of the dry emulsion process regarding the efficiency and the thermal stability of antioxidant substances.
A specific physical and/or chemical combination (such as hydrogen bond) sufficiently stable, at about 150 °C, could be suggested
when the technique used for dry emulsion preparation was SD. After water dilution, this dry emulsion obtained from quaternary
mixture: SAC, Labrafil®, SEOH and SC, will regenerate the initial liquid emulsion with the same characteristics that before drying.